The micro-coil manufacturing process involves the winding of ultra-fine wires around a core. However, during the manufacturing process, manufacturers require to join the ultra-fine wires. Micro-soldering is an effective process to join two similar or dissimilar ultra-fine wires of diameter as small as 9 microns. This article focuses on discussing the micro-soldering and micro-coil manufacturing processes.
Due to the increasing demand for microscopic parts for the components of the medical and electronics field such as sensors and transducers, the manufacturing of micro-coils has become essential. On the other hand, as the manufacturing of micro-coils involves the joining of ultra-fine wires, manufacturers have to face certain challenges due to the shape and size of the ultra-fine wires. Traditional welding and soldering methods are unable to overcome those constraints. There are several physical and environmental factors and it is also important to fulfill the ultra-strict tolerance requirements. Therefore, manufacturers can not use the traditional methods to join the ultra-fine wires.
Drawbacks of Traditional Soldering and Welding Methods:
Traditional soldering and welding methods can cause the destruction of the ultra-fine wires through imprecise heat spread. Oxidation can also occur around the wires if the traditional methods are used. There are several physical strains that the traditional methods can not overcome. Above all, the reliability of the connections can not be achieved through traditional methods. In order to overcome these challenges, manufacturers now use thermal compression bonding technology in the micro-soldering process to join the ultra-fine wires of similar or different diameters. This technology is even effective to join a wire with another wire that is twelve times thicker in diameter.
Thermal Compression Bonding:
Through thermal compression bonding technology, manufacturers are now able to manufacture corrosion-free, strain-free, and highly reliable connections. This technology is also cost-effective due to its ability to mass production. Thermal Compression Bonding is effective for the following connections such as- i) tiny copper thermocouples, ii) metal plated terminals, and iii) connections of metal to metal.
The Manufacturing Process of Micro-Coils:
There are several factors that can influence the manufacturing process of micro-coils. However, the manufacturing process mainly involves four following steps-
- First, the initial design of micro-coils is crucial as these coils are used inminiature medical devices. This step involves the calculation of the required number of winding, the diameter of the wire, and the available space for the insulated core. There are several modeling and simulation tools that can help the designing process.
- The second step involves the determination of the suitable core. Depending on the operating frequency of the device, the material of the core is decided. Before making a choice on the core, there are several other factors that need to consider. For instance, in many cases, manufacturers use ferrite or iron cores.
- The third step involves the winding of a conductor such as insulated copper wire around the core. The inductance of the coil increases with the increase in turns of wires. Therefore, depending upon the required inductance the choice of material and the manufacturing process varies.
- The final step involves the testing and validation of the finished product.